This invention relates in general to universal joints and in particular to an improved structure for restraining the bearing cups mounted on a universal joint cross from rotating relative to an end yoke connected thereto during use.
Universal joints are well known devices which provide a driving connection between two members adapted to rotate about non-aligned axes of rotation. Universal joints of this type are widely used between rotatable drive shafts in vehicle drive train systems. Typically, such universal joints include a cross having a central body portion with four trunnions extending outwardly therefrom. The trunnions are oriented in a single plane and extend at right angles relative to one another. A bearing cup is mounted on the end of each of the trunnions. Needle bearings or similar means are provided between each of the trunnions and its associated bearing cup to permit the bearing cup to rotate relative to the trunnion. One pair of opposed bearing cups is connected to a first end yoke secured to the first drive shaft, while the other pair of opposed bearing cups is connected to a second end yoke secured to the second drive shaft.
When the axes of rotation of the two drive shafts are not co-axially aligned during operation, the bearing cups rotate relative to the trunnions in an oscillating fashion so as to permit the driving connection. It is desirable that the bearing cups be fixed in position relative to the end yokes connected thereto such that no relative rotation occurs therebetween. Otherwise, wear will occur in the end yokes and the outer surfaces of the bearing cups, causing premature failure of the universal joint. Many structures are known for preventing relative rotation from occurring between the bearing cups and the end yokes. For example, it is known to weld plates onto the end surfaces of the bearing cups and to bolt such plates to the end yoke. However, this structure, as well as other anti-rotation structures known in the art, requires extra parts and additional labor to install, thus increasing the cost and complexity of the universal joint. Furthermore, such an arrangement does not readily accommodate stack-up tolerances caused by the assembly of the various components. Accordingly, it would be desirable to provide an improved universal joint with an anti-rotation structure which is simple and inexpensive to construct and assemble, and which readily accommodates such stack-up tolerances.